What methods do you know for storing and restoring system state?

In Android, the following methods are used to store and restore system state (for example, an activity or fragment):

• onSaveInstanceState(Bundle outState) and onRestoreInstanceState(Bundle savedInstanceState) — allow saving small data (primitives, Serializable, Parcelable) when recreating a component, such as during screen rotation.
• ViewModel — stores data that survives activity/fragment recreation but is not preserved when the app is destroyed.
• SharedPreferences — for saving simple settings and data between sessions.
• Databases (Room, SQLite) — for long-term storage of complex data.
• Files — for saving data in the file system.

Example of saving state in a Bundle:

override fun onSaveInstanceState(outState: Bundle) {
    super.onSaveInstanceState(outState)
    outState.putString("key", "value")
}

override fun onRestoreInstanceState(savedInstanceState: Bundle) {
    super.onRestoreInstanceState(savedInstanceState)
    val value = savedInstanceState.getString("key")
}